Hi Folks, Is there a way to create a symbol with single unit standard representation but multiple unit DeMorgan symbol?
Let’s say you have an optocoupler.
Standard symbol contains the LED and the Photo transistor (2+2pins) in single unit.
While the alternate symbol should be broken up to two units: Unit A contains the LED (2 pins) and Unit B the transistor (2 pins).
This could be handy in other examples, like you may want to “decouple” coil and contacts in a relay or keep them together as a single unit.
Is that possible? How do you create it? Any example?
Not obvious to me how, either the symbol has a single unit, or it has multiple units, no? De Morgan is about alternate graphics for a unit, not the symbol. So make 2 symbols.
No, it’s not possible. Which is a good thing, I’d say.
Welcome to the kicad forum @TSzabo.
One example : I use various 5-pin (sot-23 or sc-70) opamps with different pinouts – so different symbols. Sometimes I want power pins with the opamp, sometimes I want power elsewhere – so different symbol. The kicad symbol editor is easy to use. These are separate symbols, not demorgans.
The simplest way is indeed to just draw two (or more) different symbols. They can both link to the library entry for a footprint.
An alternative method is to draw your symbol in such a way that the two halves fit together. KiCad uses this method in it’s standard presentation of opamps. In the screenshot below. For U104 I drew all sections next to each other, while I put the power connections of U105 on top of Unit B of that symbol.
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Guys,
I’m impressed getting so many feedbacks this fast. Thanks a lot! Seems like a strong community behind KiCad.
Looks like the practical way is to create separate symbols. Assuming U3 is one symbol while U4A/B is another at @jmk’s drawing. This works for simpler parts but I think it could be very labor intensive to maintain multiple symbols for a part especially when there’re a lot of fields assigned for each (I tend to have a few beyond the standard Value/Footprint/refdes).
As far as I understand separate symbols are needed for separate packages as well since KiCad does not support pin mapping. With that a complex part (like an FPGA) could results in a bunch of symbols. Let’s say 3 different packages (not uncommon) and supporting 2 views with different number of units (driven by banks and by geometry) gives you 6 complex symbols to maintain.
Maybe I miss something…?
Thx
Not obvious to me, could you ellaborate?
Yes, but your OP was about Optocouplers and relays. FPGAs require a lot of work no matter how you treat them.
Please explain, this I’m not sure I understand
Sure. The “De Morgan” function is specifically used for having one symbol with two different graphics where you can select just one of them for your schematic. This is simple and has no unwanted side effects like double power supply pin conflicts etc.
KISS.
Your idea seems like a cauldron of different issues and functions thrown in.
That should be solved like other contributors have suggested.
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